In vehicular collisions, particularly between two vehicles of differing heights, a smaller or shorter vehicle can underrun a larger or taller vehicle, having a higher bumper or frame rail. Collisions of this type can result in severe injury and/or fatality of occupants of the smaller vehicle, as well as significant damage to the smaller vehicle as the smaller vehicle can be crushed under the larger one. Underrun protection devices (UPD's) can be positioned below a front bumper, a side rail, or a rear bumper of a larger vehicle to stop or reduce the occurrence of underrun collisions and/or to reduce the extent to which the smaller vehicle underruns the larger vehicle. These UPD's can be made of materials having relatively high mass, such as steel, and using heavy equipment, such as cranes and hoists, can be used in the installation or assembly operations associated with these UPD's. Labor intensive assembly operations, such as welding, can be used to install these UPD's onto vehicle frames.
UPD's are regulated in the European Union by the Economic Commission for Europe of the United Nations (ECE) under Regulation No. 93 (ECE-R93) for Front UPD's, Regulation No. 58 (ECE-58) for Rear UPD's, and Regulation No. 73 for Lateral Protection Devices, and vehicles sold in regions following those regulations must meet certain performance parameters set forth in those regulations. In the United States of America, the National Highway Traffic Safety Administration has a legislative mandate under Title 49 of the United States Code, Chapter 301, Motor Vehicle Safety, to issue Federal Motor Vehicle Safety Standards and Regulations (FMVSS) to which manufacturers of motor vehicle and equipment items must conform and certify compliance. In the United States, UPD's are regulated under FMVSS by Standards 223 for Front UPD's and 224 for Rear UPD's. In India, the Automotive Industry Standards Committee (AIS) has established similar standards under AIS-069 for UPD's. The Indian standards align with the ECE regulations. A summary of these performance parameters are provided in Table 1. The loads are applied longitudinally using a ram. The locations for the load applications are illustrated in FIG. 13.
TABLE 1Summary of UPD Performance Parameters inthe United States of America and EuropeFMVSSTest LoadStandard 223 &(kN)Standard 224ECE-R93 *ECE-R58 **ECE-R73Outer50kN80kN25kN1 kNedge P1Center P350kN80kN25kNOff100kN160kN100kNCenter P2Allowed125mm400mm30 mm in frontdeflectionof wheels, 300mm elsewhereHeight560mm400mm550mmThe abbreviation “kN” means kiloNewton. The abbreviation “mm” means millimeter.* These test loads apply to vehicles with a Gross Vehicle Mass (GVM) > 16 metric tons (t), for other vehicles, lower values are permitted and are a function of vehicle GVM.** These test loads apply to vehicles with a Gross Vehicle Mass (GVM) > 20 t, for other vehicles lower values are permitted and are a function of vehicle GVM.Points P1 are located up to 200 mm from the longitudinal planes tangential to the outermost points of the tires on the front axle, excluding the bulging of the tires close to the ground; points P2 are symmetrical to the median longitudinal plane of the vehicle at a distance from each other of 700 mm to 1,200 mm inclusive.The height above the ground of points P1 and P2 shall not, however, exceed 445 mm when the vehicle is unladen. P3 is in the vertical longitudinal median plane of the vehicle.
These various tests underscore the importance of these devices. Accordingly, there remains a need for lightweight, easy to assemble, underrun protection devices which can safeguard smaller vehicles in the event of a collision with a larger vehicle. To be sold in certain regions, such devices should meet the performance standards ECE-R93, ECE-R58, ECE-R73 and similar worldwide standards.